In a storage device that uses a plurality of probes to record/reproduce data, the respective probes are assigned to areas on a storage medium for recording/reproduction of data. The arrangement relationship between the areas and the probes may cause a dead space where data cannot be recorded or reproduced. Such a dead space prevents density growth of data and thus is undesirable.
In this regard, the size of each area may be increased to avoid the formation of the above-mentioned dead space. In this case, however, the probes cannot be arranged with a high density, and thus, even simultaneous recording/reproducing of data with a plurality of probes does not enable rapid recording/reproducing.